CHEM 11100 Lecture Notes - Lecture 4: Limiting Reagent, Stoichiometry, Linus Pauling

• School: University of Chicago
• Department: Chemistry
• Course: CHEM 11100
• Professor: David Mazziotti

Document Summary

From atoms to molecules ii: chemical reactions and stoichiometry. Example: 9. 53 g of cs2 reacts with excess o2 to form co2 and so2. Balance the equation: cs2 + 3o2 co2 + 2so2. Moles of cs2: 9. 53 g / 76. 2 g/mol = 0. 125 mol. Moles of so2: 1:2 ratio, so 0. 125 mol x 2 = 0. 25 mol. Mass of so2: 0. 25 mol x 64 g/mol = 16 g: limiting reactant and percent yield. Example: given the equation 16cr + 3s8 8cr2s3, how many grams of. Moles of reactants: cr: 26 g / 52 g/mol = 0. 5 mol, s8: 77 g / 257 g/mol = 0. 3 mol. Percent yield = (experimental amount / theoretical amount) x 100% Suppose protons ha and hb are separated by a distance r. also, the electron is a distance ra from ha and rb from hb. Potential energy: u(r) = ( qeqp/ra) (qeqp/rb) + (qpqp/r) where the subscript e denotes electron and p denotes proton.